Treated labdanum oil, process for producing the same and perfume composition containing the game

Abstract: A treated labdanum oil having an acid value of not more than 10, a process for preparing the same, and a perfume composition containing the same are disclosed. The treated labdanum oil is prepared by contacting a labdanum raw material with an amount corresponding to 0.5 to 10 times equivalents, based on the acid equivalent of the labdanum raw oil, of an alkaline substance. A treated labdanum oil with a clear amber-like fragrance and substantially no color can be obtained simply and at low cost.

Description: FIELD OF THE INVENTION This invention relates to a treated labdanum oil with an improved odor which is useful as a material of a perfume composition, a process for producing the same, and a perfume composition containing the same. BACKGROUND OF THE INVENTION Labdanum raw material is a black and highly viscous liquid obtained from plants belonging to the genus Cistus and is used in various perfume compositions. Labdanum raw material most in use includes labdanum gum obtained by collecting a resin separated from Cistus ladaniferus by boiling it in water, labdanum extract obtained by removing inorganic solids from the above-mentioned labdanum gum with an organic solvent, and labdanum gum distillate obtained by distillation or fractional distillation of the above-mentioned labdanum extract. However, these conventional labdanum products not only give off an undesired wood-like crude odor like cedarwood oil as well as an amber-like fragrance but assume a black to brown black color. Therefore, when applied as a material of perfume compositions for soaps, detergents, etc., they deteriorate the odor and color of the scented products. It has thus been demanded to develop a treated labdanum oil having an improved odor while retaining the amber-like odor inherent to labdanum and is useful as a material of perfume compositions. SUMMARY OF THE INVENTION As a result of extensive study, the present inventors have found that the offensive odor emitted from labdanum gum, etc. comes from acids, such as carboxylic acids and phenols, and that these acids can be removed by contact with an alkaline substance. The present invention has been completed based on this finding. Namely, the present invention provides a treated labdanum oil having an acid value of not more than 10. The present invention also provides a process for producing a treated labdanum oil having an acid value of not more than 10, which comprises contacting at least one labdanum raw material selected from: (a) labdanum gum obtainable by collecting a resin separated from Cistus ladaniferus by boiling it in water, (b) labdanum extract obtainable by extracting the labdanum gum with an organic solvent to remove inorganic solids, and (c) labdanum gum distillate obtainable by distillation or fractional distillation of the labdanum gum extract, with an alkaline substance in an amount of 0.5 to 10 equivalents, based on the acid equivalent of the labdanum raw material, and then recovering the treated labdanum oil. The present invention further provides a perfume composition containing a treated labdanum oil having an acid value of not more than 10. DETAILED DESCRIPTION OF THE INVENTION The treated labdanum oil having an acid value of not more than 10 according to the present invention can be obtained by the following process. Labdanum gum (a) which can be used as a labdanum raw material is a resin which is separated on boiling of Cistus ladaniferus in water. Labdanum gum (a) can be obtained in a conventional manner as disclosed, for example, in the pamphlet of BIOLANDES and S. Arctander, Perfume and Flavor Materials of Natural Origin, published by Elizabeth (1960). More specifically, labdanum gum (a) can be obtained by heating the plant in water and collecting the floating oily content. In this instance, an aqueous alkaline solution may be used in place of water and the resulting solution may be neutralized with sulfuric acid, followed by collecting the floating oily content. Commercially available labdanum gum may be used as such. Labdanum extract (b) which can be used as a labdanum raw material is obtainable by dissolving labdanum gum (a) in an organic solvent, such as ethanol, and removing the insoluble inorganic solid component. A commercially available labdanum extract with organic solvent may be used as such. Labdanum gum distillate (c) which can be used as a labdanum raw material is obtained by subjecting labdanum extract (b) to distillation or fractional distillation under conditions of, for example, 140 to 240°C in column inner temperature under the vacuum degree of 2 Torr. Labdanum raw materials (a), (b) and (c) usually have an acid value of from about 18 to 120. For example, Kaori no Hyakka , published by Asakura Shoten (1989), discloses that the value is from 18 to 86; while the present inventors found that the value of labdanum gum is 111. As stated above, these raw materials have a cedarwood-like woody offensive odor. According to the process of the present invention, one or more of labdanum raw materials (a), (b) and (c) is/are brought into contact with an alkaline substance, and preferably an aqueous alkali solution, followed by mixing with stirring. The alkaline substance which can be used in the present invention is not particularly limited as long as it is capable of neutralizing the above-mentioned acids, such as carboxylic acids and phenols, to form water-soluble neutralized salts. In particular, one or two or more of alkali metal hydroxides, alkaline earth metal hydroxides, and alkali metal carbonates is/are preferred, with sodium hydroxide and potassium hydroxide being more preferred. The alkaline substance is used in an amount of from 0.5 to 10 times equivalents, preferably from 1.0 to 5.0 times equivalents, based on the acid equivalent of the labdanum raw material. The acid equivalent of the labdanum raw material is calculated based on the acid value of the labdanum raw material. While not limiting, the mixing with stirring is preferably carried out at a temperature of from 0 to 150°C, preferably from 50 to 100°C, for a period of from 0.1 to 5 hours, preferably from 0.5 to 2 hours. The treatment with the alkaline substance may preferably be carried out in the presence of an organic solvent. The organic solvent may be added to the labdanum raw material in advance, or to the mixture of the labdanum raw material with the alkaline substance. The organic solvent to be used is not particularly limited as long as it is stable under an alkaline condition. Examples of the suitable organic solvent include hexane, heptane, cyclohexane, benzene, toluene, xylene, and mixtures thereof. The resulting reaction mixture is then separated into an aqueous phase and an oily phase in a conventional manner, and the aqueous phase is removed. If desired, the oily phase is washed with water and distilled in a conventional manner. The thus obtained treated labdanum oil has an acid value of not more than 10, has a markedly improved odor, and is substantially colorless. It is preferable to further subject the treated labdanum oil to precise fractional distillation to obtain a less colored and less viscous product. The perfume composition according to the present invention comprises the above-mentioned treated labdanum oil. If desired, the perfume composition may contain other components, such as diethyl phthalate, dipropylene glycol, ethylene diglycol, Hercolyn D (methyl dihydroabietate), and natural perfumes, such as sandalwood oil and patchouli oil. The ratio of the treated labdanum oil in the perfume composition of the present invention is preferably in the range of from 0.5 to 10 % by weight. The perfume composition of the present invention can be prepared by mixing the treated labdanum oil and other optional components with stirring. According to the present invention, a treated labdanum oil with a pure amber-like fragrance and a greatly reduced color can be obtained through simple operation and at low cost. The perfume composition containing the treated labdanum oil is suited for use in soaps, detergents, and the like. The present invention will now be illustrated in greater detail with reference to Examples, but the present invention should not be construed as being limited thereto. All the parts and percents are by weight unless otherwise indicated. EXAMPLE 1 In a 500 cc four-necked flask equipped with a stirrer, a thermometer, and a Dimroth condenser were charged 200 g of a commercially available labdanum extract "Labdanum Resinoid" (a product of BIO Co.; acid value: 58; acid equivalent: 0.21), 200 g of a 10 % aqueous solution of sodium hydroxide (0.50 equivalent), and 400 g of toluene, and the mixture was stirred at 90°C for 30 minutes in nitrogen atmosphere. The mixture was allowed to stand for phase separation. The aqueous layer was removed and 400 g of toluene was added thereto. The resulting mixture was stirred in the same manner as described above and allowed to stand for phase separation. After removing the aqueous layer, the organic layer was combined with the previously obtained organic layer and a 10% aqueous solution of mirabilite was added to the combined organic layer. The aqueous layer thus formed was adjusted to pH of 6 to 8 with 2 % sulfuric acid, and allowed to stand. After removing the aqueous layer, toluene was removed from the organic layer by distillation to obtain 80 g of a crude treated labdanum oil having an acid value of 0.92. The resulting crude treated labdanum oil had a clean amber-like fragrance without being accompanied by a cedarwood-like unpolished odor as compared with the starting labdanum extract. The crude treated labdanum oil was subjected to Smith distillation (140°C → 185°C/0.05 Torr) to recover 50 g of a treated labdanum oil having an acid value of 0.17. The product showed further improvements in color and viscosity. EXAMPLE 2 In a 300 cc four-necked flask equipped with a stirrer, a thermometer, and a Dimroth condenser were charged 50 g of a distillate in Smith distillation (185°C/0.05 Torr) of a commercially available labdanum extract "Labdanum Resinoid" (a product of CMA Co.; acid value: 80; acid equivalent: 0.071), 50 g of a 10 % aqueous solution of sodium hydroxide (0.125 equivalent), and 100 g of toluene, and the mixture was stirred at 60°C for 30 minutes in a nitrogen atmosphere. The mixture was allowed to stand for phase separation, and the aqueous layer was removed. To the organic layer was added 50 g of a 10 % aqueous solution of sodium hydroxide, and the mixture was stirred in the same manner as described above and allowed to stand for phase separation. After removing off the aqueous layer, the resulting organic layer was treated with a 10 % aqueous solution of mirabilite and toluene was removed therefrom in the same manner as in Example 1, whereby 7 g of a treated labdanum oil having an acid value of 3.1 was obtained as a distillate. The resulting treated labdanum oil had a cleaner amber-like fragrance as compared with the starting labdanum raw material. COMPARATIVE EXAMPLE 1 A treated labdanum oil was prepared in the same manner as in Example 2, except for using 50 g of a 1 % sodium hydroxide aqueous solution (0.0125 equivalent) as a neutralizing agent. The yield was 14 g. The resulting treated labdanum oil had an acid value of 45 and still gave out a cedarwood-like odor as compared with the product obtained in Example 2. EXAMPLE 3 AND COMPARATIVE EXAMPLE 2 A perfume composition was prepared from the components shown in Table 1 below in a usual manner. Composition (part) Example 3 Comparative Example 2 Vanillin 400 400 Patchouli oil 20 20 Sandalwood Mysore 30 30 Benzoin 40 40 Cinnamic acid 20 20 Pearlide 10 10 Acetanilide 380 380 Labdanum extract (Labdanum Resinoid, a product of CMA Co.) - 100 Treated labdanum oil of Example 1 100 - The composition of Example 3 had a pure ambergrislike fragrance with little rough woody offensive odor as compared with the comparative composition. When the composition of Example 3 was incorporated into soap, the degree of coloration of the soap was remarkably reduced.

Claims: A treated labdanum oil having an acid value of not more than 10. A process for producing a treated labdanum oil having an acid value of not more than 10 comprising a step of contacting at least one labdanum raw material selected from: (a) labdanum gum obtainable by collecting a resin separated from Cistus ladaniferus by boiling it in water, (b) labdanum extract obtainable by extracting said labdanum gum with an organic solvent to remove inorganic solids, and (c) labdanum gum distillate obtainable by distillation or fractional distillation of said labdanum gum extract, with an alkaline substance in an amount of 0.5 to 10 equivalents, based on the acid equivalent of said labdanum raw material. The process of claim 2, wherein said alkaline substance is selected form alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates, and a mixture of them. The process of claim 3, wherein said alkaline substance is sodium hydroxide or potassium hydroxide. The process of any of claims 2, 3 and 4, wherein said labdanum raw material is contacted with said alkaline substance by adding an aqueous solution of said alkaline substance to said labdanum raw material, and then mixing with stirring the mixture. The process of claim 2, wherein said labdanum raw material is contacted with said alkaline substance in the presence of an organic solvent. The process of claim 6, wherein said organic solvent is selected from hexane, heptane, cyclohexane, benzene, toluene, xylene and a mixture of them. A perfume composition containing a treated labdanum oil having an acid value of not more than 10.

Inventors: FUJIKURA YOSHIAKI, KOSHINO JUNJI, TAJIMA KATSUHIKO, TANAKA SHIGEYOSHI, TOI NAO, YAMAMOTO JUNKO, FUJIKURA,YOSHIAKI, KOSHINO, JUNJI, TAJIMA, KATSUHIKO, TANAKA, SHIGEYOSHI, TOI, NAO, YAMAMOTO, JUNKO
Applicants: KAO CORP, KAO CORPORATION
Application year: 1994
Main classification: C11B9
IPC codes: A61K8, C11B9, C11D9, A61Q13, A61Q19